It's possible that your system does not yet have the /usr/local/bin directory that streamripper's install script looks for, so you'll need to first create it:
First, go to /usr/local:
[localhost:~] chris% cd /usr/local
Check its contents for bin:
[localhost:/usr/local] chris% ls sbin
If it's not there, make it as root (with sudo):
[localhost:/usr/local] chris% sudo mkdir bin
Check again that it's there:
[localhost:/usr/local] chris% ls
However, if you've already run streamripper's install script (with "make install"), it probably installed streamripper into /usr/local and renamed that streamripper binary *file* to "bin". If so, when you do a long list, you'll see that "bin' is a file (it has a hyphen instead of a "d" at the beginning of its line):
[localhost:/usr/local] chris% ll bin
-rwxr-xr-x 1 root wheel 347892 Mar 28 10:27 bin
If this is the case, you'll need to remove that file first :
[localhost:/usr/local] chris% sudo rm bin
And then follow the step above to make a "bin" directory. You can then run the "make install" command line again without problem.
Also, if you've installed streamripper, but typing its name still doesn't find the application, type "rehash", which will force the shell to rebuild its list of known executables.
Sorry for the confusion!